Method of refrigeration and a refrigeration system

Abstract

Liquid is cooled in a batch mode. A batch of liquid is circulated in a cooling loop (12) until it is cooled to a desired temperature at which time it is removed from the cooling loop (12) and a new batch is introduced therein. Preferably, the cooled batch is discharged from the cooling loop by the new batch with as little mixing as practicable. The cooling loop has a desired volume determined by a receiver (36) of suitable capacity. A supply accumulator (14) is used to accumulate liquid to be cooled and from which liquid to be cooled is supplied into the cooling loop. Cooled liquid is discharged from the cooling loop into a product accumulator (16). The liquid may be cooled to a temperature close to its freezing point by freezing a minor portion of the liquid in the cooling loop which is then melted by the liquid of the next batch when it is introduced into the cooling loop. The cooling loop is such as to promote plug flow and to reduce backmixing. In a preferred form, the cooling loop has an evaporative cooler (32 ) which utilizes a suitable refrigerant. The refrigerant is evaporated in each cooling cycle, at a progressively reducing pressure and temperature achieved by withdrawing liquid refrigerant from a closed first vessel (92), evaporating it in the cooler (32) to cool the liquid, compressing the vapor refrigerant by means of a compressor (76), condensing the vapor refrigerant in a condenser (80) and feeding the condensate into a further vessel (94). The liquid refrigerant is withdrawn initially into a flash tank (70), vapor being circulated by a pump (72) to the cooler (32). Valves (88, 90, 100 and 102) are provided to switch the two vessels (92, 94) around at the end of each cooling cycle.

Dependencies are inferred from the claim text.